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Volcano Term Definitions
A body of igneous rocks with a flat bottom and domed top. It is parallel to the layers above and below it.
A torrential flow of water-saturated volcanic debris down the slope of a volcano in response to gravity. A type of mudflow.
Literally "little stones." Round to angular rock fragments, measuring 1/10 inch to 2 1/2 inches in diameter, which may be ejected in either a solid or molten state.
Magma which has reached the surface through a volcanic eruption. The term is most commonly applied to streams of liquid rock that flow from a crater or fissure. It also refers to cooled and solidified rock.
A tunnel formed when the surface of a lava flow cools and solidifies while the still-molten interior flows through and drains away.
Of or pertaining to stone.
The rigid crust and uppermost mantle of the earth. Thickness is on the order of 60 miles (100 km). Stronger than the underlying asthenosphere.
The reflection of light from the surface of a mineral.